Add missing _ imports to allow doc generation

Fixes bug: 1209413

Change-Id: I7d405ceb6a500cbb3d0eb19e85cb0540564e0643
Fix H231 Python 3.x incompatible 'except x,y:'

This is triggered in the pep8 check when using the syncronised
requirements versions.

Change-Id: Ie73c44b85025f79e7358303fab2697e076f7cabf
Merge "Fix H231 Python 3.x incompatible 'except x,y:'"
Merge "Add missing _ imports to allow doc generation"